<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框</title>
    <style>
        .box{
            width: 100px;
            height: 100px;
            border-width:10px;
            border-color: #369;
            border-style: dotted;
        }
    </style>
</head>
<body>
<div class="box">来吧</div>
</body>
</html>